1. Field of the Invention
The present invention relates to the field of devices used for position determination, and more specifically, to the field of Inertial Navigation System (INS)-based position determination devices with enhanced accuracy.
2. Discussion of the Prior Art
It is important to keep track of public safety personnel as they perform their duties inside buildings or other obscured and often hazardous environments. Ideally, such a system would permit continuos tracking of a large number of individuals, or movable objects, over a range of 1000-2000 feet from a tracking monitoring data collection point. In addition, other public safety personnel like policemen, or miners inside mines could benefit from such a position determination system, in that their position could be uniquely determined and sent from the in-vehicle position determination system via one of the radio systems back to headquarters for their own safety. Such position determination system could be also used to track a variety of robotic means deployed to operate in the various hazardous and obscured environments, or used to deal remotely with obscured dangerous items, etc.
The Satellite Positioning Systems (SATPSs), including the Global Positioning System (GPS), have not met the needs for tracking personnel with the availability and accuracy needed by the various management of these public safety agencies. Despite the work of various others, no products are available using SATPS (or GPS) as a wearable element in a personal position determination system. Even the enhanced sensitivity systems may encounter loss of signal in various types of buildings, such as very high rise skyscrapers, or in the deep mines. Even if enhanced sensitivity receivers can acquire signals, there is often a substantial reduction in accuracy. Furthermore, such enhanced sensitivity systems use much more power than new inertial navigation sensors. And there is the issues of the power needed to perform decent communications. The same is true in regard of tracking a variety of robotic means deployed to operate in the various hazardous and obscured environments.
Recent advances in Inertial Navigation Systems (INS) technologies makes it feasible to build a very small, low power INS system, that in combination with a similarly low power radio communications system such as embodied in a Bluetooth product, or an Ultra Wide Band (UWB) product, could provide a data link from the combination INS/Radio to a position determination system located in the fire truck, or in the police car, or in the ambulance, or in a portable station.
Thus, what is needed is to provide a mobile, or portable position determination system that receives the accelerator/velocity inputs from each uniquely identified personal INS/Radio system, and calculates a position estimate relative to the very accurate satellite-determined position of the mobile, or portable station.